The present invention relates to absorbent articles such as diapers, incontinence briefs, training pants, diaper holders and liners, sanitary hygiene garments, and the like. More particularly, the present invention relates to absorbent articles providing improved appearance and/or improved sustained dynamic fit during use.
Absorbent articles such as diapers and training pants tend to slide downward on the body of the wearer, especially when loaded with excreta. This relative movement creates gaps between the article and the body, through which leakage can occur. It also creates wrinkles that detract from the desirable garment-like appearance of the article. The designs of absorbent articles typically include features intended to sustain the proper fit of the absorbent article on the body. However, these features known in the art are only partially effective in sustaining fit, tend to cause discomfort for the wearer, and/or make application and/or removal of the article difficult.
For example, the designs of many absorbent articles depend upon a waist feature to counteract the downward force of gravity by restricting the size of the waist opening. However, the wearer of an absorbent article often has a protuberant abdomen, rather than a well-defined waist. The waist edge of the absorbent article will naturally slide downward from its initial position on the protuberant abdomen to the area of a diagonal support zone lying across the small of the back, over the hip joints, and across the lower abdomen. Some designs use friction to resist relative movement at the waist, with the waist feature providing the required normal force by generating circumferential tension around the body. However, when the abdomen becomes larger than its initial size, the waist feature naturally seeks a position of lower tension off the expanded abdomen. Because the article is restrained from moving upward, the waist feature typically moves downward toward the diagonal support zone in this situation. When the abdomen becomes smaller, the article also tends to move downward, because the tension and the frictional resistance diminish. When a waist feature is designed to generate a high force in an attempt to minimize downward movement, the greater force often causes discomfort to the wearer and/or creates pressure marks on the body. The greater force may also tend to move the article downward, and/or make spreading of the waist opening for application and/or removal of the article difficult.
The designs of some absorbent articles include side panels or waist belts which supplement or replace waist features. Examples of such absorbent articles are described in U.S. Pat. No. 6,120,487 issued Sep. 19, 2000, and U.S. Pat. No. 5,899,895 issued May 4, 1999, which are hereby incorporated herein by reference. These features tend to exert excessive force on areas of the body where they are stretched a greater amount relative to other areas, causing discomfort and/or pressure marks on the body. Also, when the elastic components move toward positions where they are stretched a lesser amount, they tend to bunch and/or slide together such that the forces they exert are concentrated on a smaller area of the body, often causing discomfort and/or pressure marking. Some side panels also expand and contract to maintain contact of the article about the legs of the wearer. In the designs of some such side panels, an elastic component is angled with respect to the main waist feature and has one end located on or near the front edge of the waist opening and another end located on or near the back edge of the leg opening. Such an elastic component which is angled downward toward the back exerts a downward force on the front portion of the article, adding to the other forces described above in tending to move the absorbent article downward and away from the position in which it is initially fit onto the body.
In some designs of absorbent articles, the front edge of the waist opening curves downward to fit below or at the abdominal crease. Examples of such absorbent articles are described in U.S. Pat. No. 5,358,500 issued Oct. 25, 1994, which is hereby incorporated herein by reference. Because they are initially fit in the area of the diagonal support zone, these low-cut articles often have better sustained fit than articles having higher waist openings. However, several desirable properties are relinquished in exchange for this improvement in sustained fit. The risk of leakage from such a low-cut absorbent article is generally greater, especially for a male wearer, whose urinary stream is often directed toward the waist. The appearance of such a low-cut article differs appreciably from that of a durable garment or of an absorbent article having the garment-like appearance desired by many users. Such a low-cut absorbent article has less area over which to distribute the absorbent core and thus an absorbent core of a given volume may generally be of greater thickness in such a low-cut article.
Thus, it would be beneficial to provide an absorbent article designed to sustain the proper fit of the article on the body. It would also be beneficial to provide an absorbent article having improved appearance throughout its period of use. It would be of further benefit to provide an absorbent article having a reduced possibility of leakage. Additionally, it would be of benefit to provide an absorbent article having easy application and/or removal.
The present invention provides absorbent articles, such as diapers, incontinence briefs, pull-on diapers, training pants, feminine hygiene garments, and the like, which may provide some or all of the benefits of improved sustained fit on the body, improved appearance through the period of use, and improved comfort for the wearer.
Such an absorbent article is intended to be fit about a wearer""s body to contain excreta and/or bodily exudates. The absorbent article has a containment assembly having a front waist region, a back waist region opposed to the front waist region, a crotch region disposed between the front waist region and the back waist region, a front end edge, a back end edge, a topsheet, a backsheet, and an absorbent core disposed at least partially between the topsheet and the backsheet. The absorbent article also has at least one waist feature disposed substantially adjacent either the front end edge or the back end edge. Furthermore, the absorbent article has at least one diagonal support member designed to support the absorbent article on the body substantially in the diagonal support zone which lies across the small of the back over the hip joints and across the lower abdomen. When the absorbent article is worn, a first end of the diagonal support member preferably lies substantially adjacent the back waist region of the absorbent article and a second end of the diagonal support member preferably lies substantially adjacent the lower abdomen of the wearer""s body.
The diagonal support member preferably bears the major portion of the weight of the absorbent article and resists downward force caused by changes in bodily shape or dimension. As a result, the waist feature may be subjected to only minimal downward force. Therefore, the waist feature may be designed to provide only enough circumferential tension to hold itself in position on the body and thus avoid causing discomfort for the wearer and/or pressure marking on the wearer""s body.
The absorbent article may thus provide a garment-like high-waisted appearance, gentle tension around the waist to avoid discomfort and/or pressure marking, good leakage protection, good sustained fit, and easy application and removal.